I wanted to offer a bit of advice as I can see this as being about as misleading as the transforming Optimus Prime toy in TF.
The attached pic is in the teaser video for Metallica.. this particular concept toy is carved out of silicone rubber (I'm guessing Smooth-On OOMO 30 by its color). It's activated by a coil behind it which shakes the whole rubber piece. It's clearly a very early concept for a toy that inevitably got scrapped for the much cheaper bobble-head toy option. A shame.. the rubber toy idea would've been pretty awesome looking. Much better than the standard dashboard bobble-head look.